Various network-based search applications allow a user to enter search terms and receive a list of search results. Such applications commonly use ranking algorithms to ensure that the search results are relevant to the user's query. For example, some systems rank such results based on reliability and safety of the search result, location of the user and search result, etc. These services may also provide business listings in response to a particular search query.
The business listing search results, or data identifying a business, its contact information, web site address, and other associated content, may be displayed to a user such that the most relevant businesses may be easily identified. In an attempt to generate more customers, some businesses may employ methods to include multiple different listings to identify the same business. For example, a business may contribute a large number of listings for nonexistent business locations to a search engine, and each listing is provided with a contact telephone number that is associated with the actual business location. The customer may be defrauded by contacting or visiting an entity believed to be at a particular location only to learn that the business is actually operating from a completely different location. Such fraudulent marketing tactics are commonly referred to as “fake business spam”.
In order to provide users with correct information, search engine companies occasionally modify their ranking algorithms to attempt to identify and exclude fake business spam listings from results presented to end users. Many spammers continually monitor changes in search engine rankings for their fake listings to determine when ranking algorithm changes occur and what those changes are. By reverse engineering spam identification aspects of the ranking algorithm, spammers can determine how to modify their fake listings to avoid spam-catching ranking penalties. Given the large number of spammers doing this, it is difficult for search engines to prevail.